Such a matrix touch sensor is known from document EP 1 719 047, constituted by a matrix network of conductive tracks disposed in rows and columns, the cells thus being defined at the location of each intersection of the rows and columns of the matrix network.
In document EP 1 719 047, the acquisition of data is carried out by sequentially scanning each cell of the matrix network, that is to say by successively powering each column of the matrix network and by successively measuring, for each powered column, an electrical characteristic at the terminals of each row, representing a level of impedance of the cell placed at the intersection of the row and of the column considered.
This sequential scanning of the cells makes it possible to simultaneously detect several points of contact on the matrix touch sensor at each scanning phase.
However, it is necessary to perform a high number of measurements at each sequential scanning phase in order to scan all the cells.
Thus, for a matrix network of cells constituted by N columns and M rows, the scanning of the sensor requires N×M measurements at each scanning phase.
Document U.S. Pat. No. 6,762,752 proposes an accelerated scanning method. In this document, in a first step, a set of columns is simultaneously powered and a sequential measurement is made for each row of a set of rows.
Next, in a second step, a set of rows is simultaneously powered and a sequential measurement is made for each column of a set of columns.
When several cells disposed on the same row and/or the same column are activated, the method identifies zones of ambiguity on which is implemented sequential conventional scanning as described above in relation to document EP 1 719 047.
Although faster, this method, alternating the axes of power supply and measurement of the cell matrix network, has the drawback of requiring connections that are reconfigurable at the inputs and outputs of the electronic measuring circuit.
The design of the data acquisition device is thus complex.